RAD-28

Compton shift

λC = 2.426 pm.

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RadiationCompton

Governing equation

\Delta\lambda=\lambda_C(1-\cos\theta)

$\theta \in \left[0, 180\right]$

where

\theta: Angle (°)
\Delta\lambda: Shift (pm)

The figure, part by part

Each numbered marker wears the color of its card. Hover a card to light the marker. Tap a marker to jump to that card. The slider walks a red point along the curve; Animate drawing traces it like a pen.

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①

Governing law — red

\Delta\lambda=\lambda_C(1-\cos\theta)

$\theta \in \left[0, 180\right]$

$\theta = 0$ $\Delta\lambda = 0$

Along the curve

②

Domain of the variable — blue

\theta_{\min} = 0,\quad \theta_{\max} = 180

$\theta \in \left[0, 180\right]$

$\theta = 0$ $\theta = 0$

Along the curve

③

Response curve — green

\Delta\lambda=\lambda_C(1-\cos\theta)

$\theta \in \left[0, 180\right]$

$\theta = 0$ $\Delta\lambda = 0$

Along the curve

④

Rate of change — amber

\frac{\mathrm{d}\Delta\lambda}{\mathrm{d}\theta}

$\theta \in \left[0, 180\right]$

$\theta = 1.132$ $\Delta\lambda^{\prime} = 8.37\times 10^{-4}$

Along the curve

Lecture brief

Historical brief

Beer attenuation, Compton (1923), Klein–Nishina, Bragg–Gray cavity and KERMA are the transport of photons and charged particles in matter. The sheets compute fluence, kerma and stopping. This sheet (RAD-28 — Compton shift) is the form associated with Compton. Working symbols: $\theta$ $\rightarrow$ $\Delta\lambda$ . λC = 2.426 pm.

Purpose

Purpose: compute

\Delta\lambda

from

\theta

in Radiation physics via

\Delta\lambda=\lambda_C(1-\cos\theta)

λC = 2.426 pm. Use it when a real radiation physics question must be answered in SI before a code check.

Live realistic example

In symbols

Live case. Given

\theta = 90.000\,\mathrm{^{\circ}}

, the governing relation

\Delta\lambda=\lambda_C(1-\cos\theta)

yields

\Delta\lambda = 2.426\,\mathrm{pm}

. λC = 2.426 pm. Move a slider: the numbers are this situation, not a canned story.

Calculator

Inputs

Angle \theta90 °

Outputs

Shift \Delta\lambda2.426 pm

Reading speed

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Narration of this film

λC = 2.426 pm.

Reading speed

Watch on YouTube